javascript error on callback after upload

I get errors on data.data.nid, telling me it's not an object, one possible solution is this (am_loader.js)

Env: FF on MacOs X

function amReturn(data, text) {
	if (data) {
      var d = data['data'];
	  if (!am_tinymce) {
  	    amUpdateTarget(d.nid, d.title, am['filter']['imagecache']);
	  }
	  else {		
		amUpdateTinyMCE(d.nid, am['filter']['imagecache']); 		
	  }
	}
  return false;
}